Tube joint apparatus for double-tube floating tunnel and construction method thereof

A construction method for a tube joint apparatus for a double-tube floating tunnel, wherein the tube joint apparatus comprises a joint device, a tunnel tube body, and an escape device;

• the escape device is provided in the joint device, the tunnel tube body is respectively connected to left and right ends of the joint device;
• a plurality of anchor yokes are connected to an outer side of the joint device;
• wherein the joint device comprises a watertight locking structure section, a framework connection section, and a main functional section;
• the main functional section comprises a joint inner road surface and a joint housing;
• the joint inner road surface is provided in the joint housing, the watertight locking structure section is connected to both ends of the framework connection section;
• the watertight locking structure section comprises a shear ring, a locking ring, and a connection ring,
• wherein the shear ring is sleeved on an outside of the connection ring, the tunnel tube body is connected to the joint device after passing through the shear ring;
• the locking ring is sleeved on a connection between the tunnel tube body and the joint device for locking the tunnel tube body and the joint device;
• a ballast tank is provided below the escape device for adjusting a self-weight of the joint device;
• the framework connection section is respectively connected to both ends of the main functional section;
• a pouring ring is provided in the framework connection section;
• the pouring ring is sleeved on an outside of the connection ring and configured to weld steel bars embedded in the tunnel tube body and the joint device;
• the tube body housing is provided with a friction ring near the joint device;
• the friction ring is a multi-ring deep groove structure and configured to increase a frictional force between the tunnel tube body and the joint device;
• the friction ring is provided in the locking ring, and the friction ring is aligned with the locking ring, there is a gap between the locking ring and the friction ring;
• concrete is poured into the gap between the locking ring and the friction ring so as to lock and fix the tunnel tube body and the joint device;
• the main functional section further comprises a second emergency channel configured to communicate two parallel tunnel tube bodies;
• the escape device is interconnected with the second emergency channel through a first emergency channel parallel to a length direction of the tunnel tube body;
• wherein the construction method comprises the following steps:
• step 1:
• prefabricating the joint device and installing the escape device, prefabricating the joint device on land, and pushing the escape device into a corresponding space of the joint device;
• step 2:
• installing a right tube section in the tunnel tube body, sealing both ends of the right tube section with a steel sealing door, installing the right tube section underwater, and dynamic positioning with a surface towing equipment;
• step 3:
• incrementally launching the joint device, sleeving the joint device onto the right tube section with an incremental launching method so that two shear rings are sleeved onto two tubes of the right tube section, and all reserved tube inner road surface main steel bars and tube housing main steel bars in the right tube section passing through the connection ring and directly reaching an interior of the pouring ring;
• step 4:
• welding and pouring the joint device and the right tube section, pouring concrete into a gap between the two locking rings on a right side of the joint device and two friction rings corresponding to the right tube section, locking the right tube section and a right end of the joint device;
• step 5:
• pumping out water between the joint device and the right tube section with a high-pressure water pump, removing the two steel sealing doors installed at the joint device and the right tube section, completing a communication between the joint device and the right tube section;
• step 6:
• installing the anchor cable, connecting the anchor cable corresponding to the joint device to its corresponding anchor yoke and seabed foundation in sequence;
• step 7:
• following the installation steps of the joint device and the right tube section in steps 2 to 5 to achieve an incremental launching between a left tube section and the joint device, thereby completing an installation of the joint device with the right tube section and left tube section;
• wherein in step 4, after the right tube section is locked to a right end of the joint device, the joint housing main steel bars buried in the pouring ring on the right side of the joint device are welded to the tube inner road surface main steel bars, the joint inner road surface main steel bars are welded to the tube inner road surface main steel bars;
• after all steel bars are welded, a formwork support is carried out, and then concrete is filled and poured.